I did (or at least made a surmise) earlier...
I would presume that it is owing to the intense regulation being imposed
on utilities that almost completely hamstrings them from being able to
expand generation (and of also transmission) capacities or even to keep
existing generation online.
In such a circumstance, anything they can do to provide incentives to
users to level peak demand is a plus.
Or, the other possibility is that it is a condition placed on them by
the State regulators. Certainly it will have been approved by same.
On 5/30/2011 1:34 PM, firstname.lastname@example.org wrote:
For residential, sure...this is commercial meter, though, not
residential even though it is light commercial where it wouldn't make
any significant difference in the (apparent) current use as given by OP.
OTOH, for "real" industrial large loads which is really the target, they
generally use control algorithms to try to maintain as near level
consumption as possible as well as maximize power factor. They do this
by phased starting/stopping schedules for the really large gear, etc.,
etc., etc., as much as is feasible within other operational constraints...
One paper mill for which I did consulting had a very sophisticated
startup sequence that relied on precise timing of motor-starting along
the >1 mile length of the line. It took something otoo 45 minutes from
the initial button press before the last set of rollers began to turn.
Another that used similar logic but that I never actually worked on was
the rolling mill making Al can stock at the Alcoa facility in Alcoa, TN.
It was a tower facility that had large feed rolls at one end and can
stock collected on rollers at the other with about a half-mile of
material going up and down in between in successive stages of the
rolling process. I always thought it kinda kewl to watch the linear
velocity increase from start to end--about 7-10X that at the entrance.
Electric arc furnaces at the Alcoa facility and other metal fab
locations are another set of very large loads where anything to level
load is a benefit financially and operationally as well.
On 5/30/2011 2:27 PM, email@example.com wrote:
Oh, sorry, missed that limited context intent.
No, I don't see it being particularly significant for residential
customers for the most part other than, perhaps, the mcmansion-type w/
spa, pool and pool heaters, maybe the heated driveway thingie, etc.,
etc., etc., ... For the casual homeowner w/ a fridge and range and
water heater, it's unlikely would make much difference. But, it would
be simple enough to deal w/ things like the water heater and other loads
not sharing "on" time.
Alcoa is where it is in large part owing to TVA in the WW II era as is
Oak Ridge (gas diffusion plants and earlier magnetic separation) for the
Manhattan Project. Rural at the time w/ plenty of water for power.
Kingston Fossil was built subsequently for the expansion of the
facilities during the '50s arms race.
While relatively close, the Al plant isn't right next door to generation
facilities but the smelter is closer. It's kinda spooky driving along
I40 when one of the loaded flatbeds passes at about 80-85 mph w/ that
vat of hot Al on the way to the casting mill. There have been a couple
of accidents where they've spilled one; it tends to leave crispy things
all around... :(
On 5/30/2011 3:21 PM, firstname.lastname@example.org wrote:
Indeed. I would guess the limitation for residential is in transmission
and substations as growth continues to get more spread out from urban
centers. Little of that is directed to or through the areas that would
be serving the heavy industrial users so don't think it would make much
difference for most utilities from that standpoint.
I could see that load leveling could, on a wide-enough scale,
potentially allow one to forestall otherwise necessary retail market
grid enhancements as a potential (altho distribution wasn't my primary
area when doing work w/ the utilities; I was mostly generation-side I&C
R&D for enhanced measurements during most of time w/ the fossil guys;
prior to that while still in the nuke generation arena it was all very
physics oriented and very little to do w/ anything more than remotely
connected to actually generating power--only in that it took somebody to
keep the reactors purring to boil the water in the SGs and deep in the
bowels of the computational physics models used for those calculations
are my thumb prints... :) )
On 5/30/2011 1:34 PM, email@example.com wrote:
Peak and off-peak isn't all that easy with the old meters, but I thought
that was one of the capabilities of the new "smart" meters. Also
'talking' to the occupant.
Demand is a common method for utilities to level the peaks for reasons
that have been well covered. Around here the demand shows up as a
penalty charge, not a kWh rate multiplier. For industrial metering
"reactive power" (kVARh) metering is also pretty common - again a
penalty charge. The penalties are high enough to provide a real
incentive. Some installations with backup power run the backup to shave
If I had the questions Home Guy did I would talk to the utility. Leave
the door unlocked? Why repeated numbers? Why wide variation? Estimates?
With a 400A service the current metering will use current transformers.
There is likely a CT cabinet with a utility seal. Unless the disconnect
is ahead of the CT cabinet I don't see a reason why the door can't be
left unlocked. I don't see why it can't be unlocked anyway - the
occupant has to have access to the disconnect.
Demand metering requires a demand meter, too. Peak/off-peak metering has been
done for decades without "smart meters", though usually with two meters. FWIG,
almost all old-style mechanical meters will be gone in a short time.
On 5/30/2011 10:11 PM, firstname.lastname@example.org wrote:
I maybe should have said more.
A demand meter will show a "demand", which is kWh over a short time
period, maybe 15 minutes. The maximum demand for the billing period is
indicated and read, and the demand register is reset. I haven't looked
at a utility rate structure, but basically the kWh demand is multiplied
by a $number to give a penalty which is added to the bill. The higher
the kWh demand the higher the penalty.
The penalty can be quite high and provides an incentive for the customer
to use one of many "peak shaving" techniques.
Similarly the VAR meter (which for mechanical meters is a second meter)
registers the reactive power 'used'. (This flows from the utility and
back to the utility and is not actually used.) The kVARh in the billing
period is multiplied by a $number to give a VAR penalty which is also
added to the bill.
This penalty is high enough to promote using power factor correction
caps, or other techniques, to improve the power factor.
The utility can, and does, correct the power factor. They can also
improve the power factor caused by harmonics (I don't know if utilities
do). They can't fix high demand.
Yes, I have the time to entertain tangents to the thread I started,
which includes showing what a moron you are when you don't read what
others have posted.
Why do you refuse to admit you were wrong? Diversion isin't an answer.
Your quote is not a cut/paste of the actual words, which is too bad; looks
like you paraphrased it to suit yourself or t was somehow not the rght one
as it doesn't mention residential/company connections and several other
things. That one very gross spelling error hurts you too; it stands out like
a sore thumb.
Sure you can. I do it all the time. Some can't be edited (depending on how
it was created) or cut but just because it's a PDF doesn't mean you can't
cut-n-paste from it. You can highlight, underscore, add notes, and do a *lot*
of things to a PDF.
You are too focused on the total billed number of kWh to see why
a demand meter is used for electrical services with a main disconnect
rated over a certain amperage...
A customer with a steady draw (demand) of 2.7 KW over 30 days to
end up being billed for 2,000 kWh over the course of a billing period
is *MUCH* easier for a power company to serve than a customer
whose draw is 500 KW a couple of times during the same billing period
and winds up with the same 2,000 kWh of use...
To serve the second customer whose demand is erratic and might
come at a time when the local power grid is overloaded requires
the power company to provide beefier service lines in that area
and have the capacity to accommodate that erratic load without
tripping safety devices in the power grid or browning out other
You just don't seem to understand that the greater the amount
of power a customer needs to use at the same time (peak demand)
is more important than the total of the kWh that customer is billed
for during any given period... Whether you use 1 KW for 2,000 hours
or 2,000 KW for 1 hour makes a difference in how the power company
serves you as far as equipment and capacities...
Again whether or not you have a demand meter depends on the
purpose of the occupancy and the amperage rating of the main
disconnect... A home with a 100 or 200 amp main service would
usually not have a demand meter, but a home with a 1,200 amp
main disconnect very well might have a demand meter installed...
Just because you are only using 2,000 kWh a month in your building
is meaningless... Your building is equipped with service entrance
equipment which could supply it with far more power if you were
doing things that needed it...
You clearly do not possess enough information or knowledge to
be of any use describing what service equipment you have installed
in your building... You say you are only using 120/208 3-phase
power, well you have no idea what your building is being supplied
with, it could have a 400-amp 277/480 3-phase supply which would
mean that you are only using one or two sub panels fed by an
on premises transformer...
It is *NOT* the power companies' fault that your building's electrical
facilities are GROSSLY over sized for the current occupancy that
you are using it for... But that is nothing the power company nor
the PUC will ever worry about -- as long as your building is equipped
with the service entrance equipment which has 400-amp capacity
you will never be able to get rid of the "demand meter" even if your
actual power usage is very low at approximately 2,000 kWh a
If it is _that_ important to you to no longer have a "demand meter"
then you can hire an electrician to remove the old electrical service
equipment and install a smaller service in-line with what your
actual power consumption is, but until you have all the old power
panels and service head removed from your building, the power
company WILL NOT install a non-demand meter for your building...
You can ask RBM how much that would cost, depending on the
sq. ft. of the building it can be expensive...
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